Electrostatic discharge protection device having a graded junction
US6365937B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1999 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | May 12, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/14
Abstract
An electrostatic discharge protection device for integrated circuit is formed in a substrate and contains pad contact, rail contact and a deep oxide in a trench in the substrate which isolates pad and rail contacts. The substrate is doped with a first dopant type with a first concentration. A second dopant type in a first inner and a first outer region forms the pad contact; both regions are formed on the substrate. The first inner region is doped higher than the first outer region. Similarly a second dopant type in a second inner and a second outer region forms the rail contact; both regions are formed on the substrate. The second inner region is doped higher than the second outer region. Buried layers are formed of the first dopant type in a second concentration under the pad and rail contacts and under the deep oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.